Prior art collator designs have been based upon several distinct approaches. One such approach is to employ a separate deflector at each document-receiving bin for intercepting documents transported along a path across the bin openings. Examples of multiple deflector devices are shown in U.S. Pat. Nos. 1,237,646 and 2,661,209. The prior art multiple deflector collator/sorters are useful for high-speed and/or random-sequence sorting but are expensive to construct and, unless carefully designed and manufactured, are frequently unreliable in operation because of the large number of moving parts.
Other prior art approaches include bins either linearly or rotationally moved relative to a fixed location document distributor. These devices suffer from the disadvantage of having a relatively large mass which must be quickly and accurately moved. Thus, the relatively slow speed of operation and complexity of mechanisms are significant disadvantages for such apparatus. Yet another prior art approach is to employ an elongated document distributor pivoted around a point to form a path to the bin openings as shown in U.S. Pat. No. 2,076,391. The pivoted distributor approach is not well suited for reasonably usable numbers of receiving bins, especially since the size of the device becomes unacceptable for convenience copier environments.
Finally, single-moving deflector collators have been developed which have reasonable operating speed and reliability for many applications. An example of this approach is taught by prior art U.S. Pat. No. 2,328,317 which describes a large collator adapted for collating sheets or distributing similar objects into a multiple-shelved receiver. These receptacle shelves or bins are arranged in spaced parallel relation to each other forming a column or stack. All bin openings or mouths are ordered in a straight course or path, along which the articles to be distributed are transported by a conveyor system composed of continuous or cloed loop belts. The documents to be collated are positively retained between these continuous belts for transport along the straight course. This conveyor system is continuously driven by a first motor mounted to the frame of the collator. To divert or deflect the articles to be distributed into the respective bins, a single deflector assembly is operatively associated with the conveyor and is mounted for movement along the conveyor in the same path as the articles along the entrance mouths of the bins. Movement of this deflector assembly is accomplished by a cable system driven over a reversing clutch by a second motor mounted to the collator frame. An indexing mechanism controls positioning of the deflector assembly at predetermined positions along the conveyor path or course for deflecting moving documents therefrom into selected ones of the receiver shelves. Since the documents or articles to be collated are positively held by the belt-like conveyor system up to the openings of the slightly sloped shelves, the apparatus is substantially independent of particular horizontal or vertical orientations of the device.
While the movable deflector mechanism described in U.S. patent application Ser. No. 778,765; filed Mar. 17, 1977, named above, operates well, it employs numerous gears and other parts which provide weight and noise to the configuration. Since the collator is for special use on office copier machines, it is desirable to eliminate as much noise as possible since they are found in office environments. It is an advantage of the present invention that numerous parts and corresponding weight in the collator mechanism have been eliminated with a concomitant reduction in the amount of noise provided from the collator. Additionally, the collator design found in the above-mentioned patent application, when used with an office copier machine, is somewhat dependent upon long paper paths in which the sheet of copy paper has left the final processing station of the machine before it reaches the collator area. In that manner, transport means within the collator for feeding the copy sheet into the collator bins can be operated at a speed substantially higher than the speed at which the copy paper moves through the processing stations. Such a speed differential is desirable because it enables the copy sheets to be accelerated into a bin so that the movable deflector has additional time to move to the next bin and can be accurately positioned well before the next sheet of copy paper arrives from the machine. The provision of machine independent speed for the transport means also creates the capability of matching the speed to the requirement of pushing the paper into the receiving bin at an optimum velocity. This invention is designed to accomplish a similar result in a machine with a short paper path in which the paper has already entered the area of the transport means at a time in which it is still in a machine processing station. In such a machine, the transport means should be operated at machine speed while the paper is still within machine processing stations, but should be accelerated to an optimum paper-expelling speed once the paper is out of the last processing station. This invention provides an independent, multiple-speed drive for the transport rolls.
Another disadvantage of the collator described in U.S. patent application Ser. No. 778,765; filed Mar. 17, 1977, is that it can move to the appropriate bin from one direction only. In a copier machine in which it is desired to produce duplexed copies by manually removing the single-sided sheets from the collator and placing those sheets in the paper drawer upside down so that the second side can be copied on the blank side of the first copy, the one-direction only collator creates problems. Note that the collator "backstacks" copy paper, i.e., the first sheet entering the vertical collator bin is positioned nearest the machine from which it came. Backstacking is advantageous since the result is side one on top when papers are removed from the bins. However, when producing duplexed copies, it is desirable to move the deflector backwardly on the first pass, i.e., to move the deflector from what would normally be bin 10, for example, toward bin 1. In that manner side one can be stacked in bin 10, side three can be stacked in bin 9, side five in bin 8, etc. As a consequence, when the operator of the machine removes the paper from the collator, all the blank sides of sheet one will be on top and will be so positioned in the copy paper bin. Therefore, the blank sides of sheet ones are fed into the machine first to receive an imprint of side two. In that manner the operator is not required to feed the original documents in reverse order on the second pass. Unfortunately, the deflector mechanism described in the above-mentioned patent application is incapable of moving to a selected bin from either direction. This invention solves that problem by providing a simple and light-weight, noise-free, low-cost deflector mechanism capable of selecting bins while moving in either direction by providing an independent electric motor to move the deflector in either an incrementing or decrementing direction, or both.